This relates to digital image processing and, particularly, depictions of motion blurring and compression techniques.
Motion blur is generated when the shutter of the camera is open for a finite time, and some relative motion appears inside the field of view of the camera. It is an effect that is important for offline rendering for feature films, since the frame rate is rather low (˜24 frames per second). With motion blur in the rendered images, apparent jerkiness in the animation can be reduced or removed entirely. However, motion blur is also becoming an important visual effect for real-time rendering, e.g., for games. In order to get good performance, various rather crude approximations, that may or may not apply in all cases, are used.
In general, motion blur rendering can be divided into two parts, namely, visibility determination and shading computations. Most solutions that converge to a correctly rendered image are based on point sampling. The more samples that are used the better image is obtained, and at the same time, the rendering cost goes up. In many cases, one can obtain reasonable results with rather few shader samples compared to the number of visibility samples. For example, RenderMan uses only a single shader sample for motion-blurred micro polygons.